Ni²+, Zn²+, Mn²+

Question 1

Ni²+ + NaOH mention colour too

Answer 1

Ni(OH)2 (green ppt)

Question 2

Is Ni(OH)2 soluble in NaOH or aq NH3? What product does it give?

Answer 2

It is not soluble in NaOH but soluble in aq NH3 to give (Ni(NH3)6)²+ (deep blue)

Question 3

Ni²+ + NH4OH

Answer 3

Ni(OH)2

Question 4

Ni²+ + CN- mention colour too

Answer 4

Ni(CN)2 (green)

Question 5

With excess CN- Ni(CN)2 gives [Ni(CN)4]²- which is a yellow solution , true or false?

Answer 5

True

Question 6

Ni²+ DMG +NH⁴+ mention colour too

Answer 6

[Ni(DMG)2] (brown red or cherry red ppt)

Question 7

Zn²+ H2S /NH4OH mention colour too

Answer 7

ZnS(white ppt)

Question 8

ZnS + dilHCl

Answer 8

ZnCl2 + H2S

Question 9

ZnCl2 + NaOH mention colour too

Answer 9

Zn(OH)2 (white)

Question 10

Zn(OH)2 + excess NH4OH

Answer 10

[Zn(NH3)2]²+

Question 11

K4[Fe(CN)6] + Zn²+ mention colour too, is the product soluble in NaOH , whats the product?

Answer 11

K2Zn3[Fe(CN)6]2 (white), in NaOH the product is : [Zn(OH)4]- + (Fe(CN)6)⁴-

Question 12

Mn²+ NaOH mention colour too, what does it give in excess NaOH

Answer 12

Mn(OH)2 (white), in excess : MnO(OH)2 (brown)

Question 13

Mn²+ + NH4OH , where does equilibrium go?

Answer 13

Mn(OH)2 + NH⁴+ but here equilibrium goes backward

Question 14

Mn²+ + PbO2/S2O8²-/BiO3-

Answer 14

MnO4- + Pb²+/SO4²-/Bi³+